Default Route for eth1 in AWS?

Is there a best practice configuration to assign a default route (0.0.0.0/0) in AWS on interfaces other than the mgmt interface?

 

I have traffic hairpinning through a VIP -> SNAT (to maintain its public IP address) and egress via the public IP address it entered on.

 

As soon as a I try to configure a default route on eth1, all egress traffic stops.

 

Any ideas?